We are having a very strange problem with one of our clients. Everyone is able to send email to external email accounts, everyone in the company except one user is able to email internally. This one user can send emails externally but not to anyone else internally, they don't get bouncebacks or anything, the email just doesn't arrive at the other end. I have run the BPA and it reports no issues, message tracking center also shows the messages being delivered. The user receives internal emails and no other users are having the same issue.
The environment is Server 2008 R2 with Exchange 2010 installed, they recently migrated from an Exchange 2003 environment, I have configured an anonymous receive connector so that
internal scan to email type emails work.
I have disabled the message scanning part of Eset Mail Security and have checked Messagelabs which doesn't show any messages being blocked either, not sure what else to check!